Factors influencing mutual gaze in captive female Japanese monkeys (Macaca fuscata)

Mutual gaze occurs when two animals simultaneously look at each other, and therefore signals reciprocal visual attention. We studied the occurrence of mutual gaze among adult female Japanese monkeys (Macaca fuscata) housed at the Central Park Zoo in New York City (USA). We found that the frequency of mutual gaze varied according to one aspect of social context (proximity), and that monkeys' age-rank was negatively correlated with the frequency of mutual gaze. The behavioral contexts in which mutual gaze was observed did not include aggression, and social rank did not predict frequency of mutual gaze. Mutual gaze therefore varies according to some aspects of social context and is generally predicted by factors that influence other social behaviors (e.g., age).